Generally, the treatment for permanent wave is carried out in a following process. In that process, the hair is wound around a rod and a first permanent wave treatment agent containing reducing agent is applied to the hair. In this condition, the hair is left under the room temperature or heated to soften and swollen the hair and the reducing agent applied to the hair is washed out. Next, a second permanent wave treatment agent containing oxidizing agent is applied to fix the binding inside the hair by oxidizing and after that, the rods are removed and the second agent is washed out and then the hair is dried.
However, although this general permanent treatment method is an art which has prevailed generally, this has a disadvantage that the wave of the treated hair is expanded (becomes slack) when dried and its period of maintaining the wave is not sufficiently satisfactory.
Recently, a heating rod has been developed, this rod being heated directly by supplying current to the rod having a heater disclosed in Japanese Patent Application Laid-Open No. 2005-402 and a new permanent wave treatment method using this heating rod has been proposed. According to this new permanent wave treatment method, after the hair is softened and swollen by treatment with the first agent, the hair is wound around the heating rod and heated/dried. Consequently, waves that are less weaken (less slacken) than conventional ones when dried are formed. If an apparatus for drying the hair is applied for permanent wave treatment, use of a drier which has been used as an apparatus for setting the hair conventionally can be considered.
This apparatus includes art of drying the hair by making a rod in which air can be passed through, disclosed in Japanese Patent Application Laid-Open No. 2002-272529 blow hot air from inner peripheral face and outer peripheral face of the rod and an art in which part of the hair is wound around a hair winding cylinder having a rotatable slit and dried with the interior of the cylinder kept in a negative pressure while blowing hot air to a rotated cylinder as disclosed in Japanese Patent Application National Publication No. 4-503915.    Japanese Patent Application Laid-Open No. 2005-402    Japanese Patent Application Laid-Open No. 2002-272529    Japanese Patent Application National Publication No. 4-503915